ABSTRACT ? Core C The Ovarian SPORE Biostatistics Core provides statistical collaboration and data management support for each of the main SPORE projects, the Developmental Research and Career Development projects, and the other Cores. In Years 1-5, Core members have collaborated heavily with SPORE researchers to facilitate optimal study design, create analysis plans, and interpret results. Biostatistics Core members have been co- authors on more than a third of the SPORE's 136 publications in the first five years of funding. In addition, Core members also improved the data infrastructure by migrating two previously existing databases for clinical data and patient registration data into one Ovarian Clinical Database (OvCD). This migration has resulted in improved efficiencies for Biostatistics Core members as well as study coordinator staff. This database is utilized not only by Ovarian SPORE researchers, but also by institutional ovarian cancer researchers. It is a source of accurate, up-to-date information and has facilitated inter-SPORE collaborations. In this renewal, the Biostatistics Core has been very active in preparing the statistical plan for each Project. The Biostatistics Core will continue to assure each SPORE investigator access to statistical expertise that includes collaborative development of study designs and analysis plans, state-of-the-art data analysis and interpretation, data management resources, and abstract and manuscript preparation. The proposed projects span a wide range of approaches and analyses. In addition, Core members will continue to improve existing database infrastructure, including continued development of a patient derived xenograft (Avatar) database which is complementary to and will synchronize Avatar data with the existing OvCD. The Biostatistics Core builds upon the innovative and time-tested procedures and systems developed by Mayo Clinic, one of the largest statistical groups in the country, whose members have collaborated on clinical and basic science research studies since 1932. This Core complements and assists the efforts of the Biospecimens/Patient Registry Core and Animal Models Core by providing superior data management and experience with biospecimen registries. Through these collaborative activities, the Biostatistics Core will help assure that research in this SPORE is carried out in an efficient, effective, and rigorous manner.